What should I know about bilirubin and blood test?
Picture of blood test result showing Bilirubin, AST, ALT levels.
- Bilirubin is a reddish yellow pigment made during the normal breakdown of red blood cells.
- Normal levels vary slightly from lab to lab; they range from about 0.2 – 1.2 mg/dL.
- Signs and symptoms of high bilirubin levels in adults vary with the underlying cause; however, symptoms usually include jaundice and itching.
- High bilirubin levels in adults usually means that there may be an underlying problem involving the red blood cells, liver, or gallbladder; however, other problems also may be found.
- Symptoms of high bilirubin levels in newborns are skin and/or scleral jaundice.
- High bilirubin levels in a newborn means that the neonate is not processing red cell breakdown effectively or an underlying cause is responsible.
- The treatment for elevated bilirubin in adults depends on the underlying problems. Experts suggest avoiding alcohol.
- The bilirubin test can chemically determine the total and if needed, the conjugated and unconjugated levels of bilirubin in the blood.
- The bilirubin test is performed on a small sample of blood from the patient.
- You prepare for a bilirubin test by refraining from eating for a few hours and avoiding certain compounds that influence bilirubin levels before the test.
- Risks associated with a bilirubin test are minor.
- The prognosis for an adult with elevated bilirubin levels is related to the underlying cause, and may range from good to poor.
- The prognosis for a newborn with elevated bilirubin levels usually is good in the majority of newborns if they rapidly reduce their bilirubin levels.
- High bilirubin levels can be prevented in neonates by early treatment, and presented in adults by treating the underlying causes and avoiding alcohol or other substances that may damage the liver.
What is bilirubin?
Bilirubin is a bile pigment that is orange-yellow in color. It is formed
during the normal breakdown of red blood cells (hemoglobin), and is excreted in
the bile. Bilirubin can be classified as indirect (free or unconjugated) while
it is circulating and is considered as direct after conjugation in the liver
with glucuronic acid.
What are other names for bilirubin?
As stated previously, bilirubin usually exists in two forms in the body.
Unfortunately, the two forms have several different names that appear frequently
in the literature. Additionally, the medical literature frequently uses the
single term "bilirubin" to describe the two forms. Frequently, the medical
literature does not distinguish between the two forms, and this can be confusing
to the reader. In an attempt to clarify the situation, below are listed the two
forms and their names and synonyms:
Bilirubin – a term that means any form
of a yellowish pigment made in the liver when red blood cells are broken down
and normally excreted with the bile; also termed "total bilirubin."
- Bilirubin can be classified as indirect
while it is circulating in the body. In this form it may also be termed "free"
or "unconjugated bilirubin."
- Bilirubin can be classified as direct
after conjugation in the liver with glucuronic acid. This form may also be
termed "conjugated bilirubin."
- Neonatal bilirubin - total bilirubin in
neonates (conjugated and unconjugated bilirubin)
What is the bilirubin test?
The bilirubin test measures the total bilirubin level (unconjugated and
conjugated bilirubin) spectrophotometrically. A subset of this test is designed
to measure or estimate the two major forms of bilirubin, unconjugated and
conjugated bilirubin. Although blood is usually tested, amniotic fluid and urine
also can be examined. In addition, newborns can be scanned transcutaneously with
a device to check bilirubin levels.
Hepatitis C, Hep B, Hep A: Symptoms, Causes, Treatment
Jaundice Symptoms and Signs
Jaundice is caused by abnormally elevated or high blood levels of bilirubin.
Signs and symptoms of jaundice include:
- The yellow staining of the skin and the whites of the eyes (sclerae)
- Dark urine
- Pale-colored stools
- Nausea and vomiting
What are symptoms of high bilirubin levels in adults?
In adults, jaundice (yellowish coloration of sclera the eye and/or the
skin) and itching are the major symptoms
and signs of elevated bilirubin levels in the blood.
The following are some of the potential underlying causes of elevated bilirubin and associated
and their associated symptoms and signs (this is a short list, not complete
(red blood cell destruction as a cause) symptoms and signs include
Viral hepatitis symptoms and signs include
Biliary obstruction symptoms and signs include
Signs and symptoms of infections (for example,
Genetic diseases (for example, sickle-cell disease, and
hereditary spherocytosis) have symptoms and signs of
Liver (hepatic) causes (for example, cirrhosis, liver
drugs, toxins, Gilbert's and Crigler-Najjar syndromes) include symptoms and
- abnormal liver enzymes, and
- liver masses.
What are the symptoms of high bilirubin levels in adults?
High bilirubin levels in adults may indicate several types of problems, for example:
- Red blood cell breakdown is more than usual (for example, a blood transfusion reaction)
- Liver scarring
- Liver inflammation
- Other diseases of the liver such as infections
- Dysfunction of the common bile duct
- Cancer of the pancreas or gallbladder
What are the symptoms of high bilirubin levels in newborns?
High bilirubin level in the newborns usually is indicated by jaundice of the
skin, usually appearing on the face and forehead first, and later spreading to
the trunk and extremities. Other changes such as drowsiness, seizures and
altered crying may occur if high levels persist. Some newborns may have
petechiae, an enlarged spleen and anemia due to hemolysis and can progress to
develop neurologic problems or even death.
How do I prepare for the bilirubin test?
- In general, patients are often asked to fast (only drink water) for several
hours before the test.
- Avoid strenuous
exercise before the test
as this may elevate bilirubin
- Avoid drugs such as
caffeine, penicillin, salicylates, and others
as they can
decrease bilirubin levels.
How is the bilirubin test performed?
- The test is performed by withdrawing a small amount of blood from the
- This blood sample is then chemically screened for bilirubin.
- Chemically, subset
test can determine both unconjugated and conjugated bilirubin levels.
Bilirubin (Bilirubin Test)
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What are normal bilirubin levels in adults?
- Normal values of direct bilirubin range from 0 to 0.4 mg/dL.
- Total bilirubin (direct and indirect) range from about 0.2 to 1.2 mg/dL
(some lab values range as high as 1.9 mg/dL). Medical literature sources have
minor variations in "normal" levels).
- Low levels of bilirubin may be due to certain
medications such as theophylline
(Elixophyllin, Theo-24), phenobarbital, and increased
vitamin C levels.
What do high bilirubin levels in a newborn mean?
High bilirubin levels in a newborn usually is the result of unconjugated
bilirubin, and is not a major problem for many newborns because they soon metabolize the unconjugated bilirubin
normally. These neonates usually clear
jaundice within a week. However, very high unconjugated bilirubin levels over
time (weeks) can be neurotoxic and can even cause death or lifelong neurological
problems (kernicterus) in those who survive. Newborn jaundice may be the result
of an underlying problem, for example:
- A family history of
- Genetic problems
- Birth trauma
- Maternal drug intake
- Viral infection or a
problem with bleeding
- Liver and/or bile function
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What is the treatment for elevated bilirubin in adults?
The treatment for elevated bilirubin in adults is to first determine the
underlying cause for example,
- clot reabsorption,
- hemolytic anemia, and
- liver and/or bile problems.
Experts suggest avoiding alcohol consumption to prevent further liver
What risks are associated with the bilirubin test?
associated with this test are minor; and consist of potential infection at the
blood withdrawal site, and possible bruising at the site.
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What is the prognosis for newborns?
In general, newborns have a good outcome if the bilirubin levels decrease
quickly (over a few days); however, the prognosis is not good if the newborn has
persistently high bilirubin levels.
Can high levels of bilirubin be prevented?
High levels of bilirubin may be prevented in neonates by appropriate
treatment. Primary therapy for newborns is phototherapy, followed by exchange
transfusions and intravenous immunoglobulin. Your newborn's pediatrician will
help manage your newborn's bilirubin levels.
Management of high levels of bilirubin in adults vary with the underlying
cause. In general, though, adults with elevated bilirubin levels are urged not
to drink alcohol, and to avoid any compounds that may harm or stress the liver's
function. Your health-care professional can help you determine what you should do, and what you
should avoid depending on your underlying problem that is causing the elevated
What is the prognosis for an adult with elevated bilirubin levels?
The prognosis in an adult with high bilirubin levels may range from good to poor, depending upon the
underlying cause of the elevation. For example, most
hepatitis A patients recover completely while patients with liver cancer or
cirrhosis may have a poorer outcome.
Liver disease refers to any abnormal process that affects the liver.
Medically Reviewed on 7/12/2019
Nazer, H. "Unconjugated Hyperbilirubinemia." Medscape. Updated May 02, 2016.
Weisinger, R. "Conjugated Hyperbilirubinemia." Medscape. Updated Jan 05, 2016.
American Association for Clinical Chemistry. "Bilirubin." Updated Sep 17, 2015.